Bomb sight



l s 968 s 127 @gmail-1 Room( QHUSSREFERENCE `July 31,1934. flgssgla A. CLEMENT! BoMB'sIGHT Filed April 12. 1932 l 'Patented July 31, 1934- V1` ATENTporriCE i UNITE-o STATES BOMB SIGHT Antonio Clementi, Vienna, Austria, asslgnor to the rm Acticngesellschaft C. P. Goetz Optische Anstalt Actiova Spolecnost K. P. Goetz Optick-y f Ustav, Bratislava, Czechoslovakia, a company of Czechoslovakia Application April 12,1932, Serial No. 604,795 In Germany April 20, 1931 2 Claims. (Cl. 3HE-5) The object ot the present invention is to provide an apparatus ior determining readiLy,-`reliably and without the use of an auxiliary target the angle at which an object such as a bomb, a

l post bag or the like has to be dropped from an air craft for hitting a predetermined point.

With this object in view, according to the present invention the aiming apparatus comprises two sighting rules rotatably mounted on a horizontal pivot pin carrying a sighting mark common to gg extent that the angle between the sighting line of the aiming rule and the vertical is equal to the angle required in order to hit the target.

The drawing illustrates by way of example an embodiment of the present invention. Fig. 1 ilg5 lustrates the geometrical principle of the present apparatus, Fig. 2 is a side elevation of the aiming apparatus with a sighting rule guide for high altitudes, Fig. 3 is a plan viewof Fig. 2 and Fig. 4 is a transverse section of a sighting rule guide for high 3g ang 3low altitudes, on the line liv-IV, Figs. 2

In Fig. 1, Ks is a sighting point in the axis of a pivot pin common to the iirst sighting rule KQK and the aiming rule KDKU. At the moment at which the'target Z appears in the sighting line of the rst sighting rule KDK' the predetermined measuring period t begins, i'or instance 10 seconds, during which the rst sighting rule is so turned by hand, say by shifting backwards o a support M of this rule, that the target is kept in this sight line during the whole measuring period. This predetermined measuring period is independent of the height of the aircraft above the ground. At the end of this period the point l4g, M will have reached the position M', MM' being equall to S, and the rule KOK will have reached the position KQK'q the target having moved, as it were, into the position Z', ZZ=vt being the distance by which the air craft. flying horizontally with the speed v towards the target,`has approached the target in the measuring period. The other sighting rule KeK'u, turning around the point Ks, is simultaneously moved from its vertical initial position in a direction opposite to that of the movement of the rule' KuK by shittsented by ing forwardly in a horizontal manner, its supporting point, which is located above the horizontal line of movement of the supporting point M or below this latter line at No or N'o respectively, according to whether the altitude or time '30 or fall is long or short respectively, so that this supporting point reaches in the measuring period t the position N1 or Ni, the distances NQN@ and' NiN'i being exactly equal to the distance MM', that is to say equal to S. If now at-the end of the measuring period t the forward movement of the supporting point N is automatically stopped a then the lines KsNi or KnNi would indicate by' their points of intersection Z"Z"1 respectively.

with the horizontal plane passing through the i ,Y

target, at which points an object dropped from the air craft at the end o the measuring period would reach the said horizontal plane, provided the horizontal component of the speed of the ob# ject were at all times exactly that of the horizontal speed of the air craft, the distance between the points Z" and Z1 and the point of intersection Zo of a perpendicular from the air craft with the horizontal plane passing through the target is UT and vTi respectively. But ow- 50 ing to the resistance of Ythe air the object thrown off lags behind the air craft which moves with a constant speed, by an amount defined by the lagging angle, the tangent of which isreprer r' n f n respectively, wherein n is the height of 'night .forhigh altitudes or long'falling times and H 00 that for low altitudes or short falling times, and r and .r'respectively are the distances by which the actual hitting points 'Z'r and Z'1r respectively are in rear o1' the theoretical hitting points 2"' and Z"1, respectively.

For securing a sighting as exact as possible the outer sightv mark is located as far as possible from the inner sight mark Ku, that is to say not at the rule supporting point Nr or Nr, but at Kr or Kf for the initial position of the dropping rule in which the hitting point Zr is at a legging distance r for high altitudes or long falling times and the hitting point Z'r is at a lagging distance 1" in rear of the point of intersection Z0. Therefore .at the moment of dropping if lagging is taken into account, the sighting rule mustv be in the position KsZ'r or KoZn, that is to say, on the sighting line 'KsKr-K", or KONnKfir. Ii the point K0 is at a distance C from the horicontar guide s's'.' or the supporting point of me 110 'i rule and the falling times T is greater-than the constant measuring period t, it follows from the g two triangles KnZZf and KoNnNi that:

. t v a This equation gives positive values for T t and negative values for T t and thus in the latter case the horizontal guide of the supporting point N of the rule must be below the horizontal guide of the supporting point M.- The negative adjusting height is designated by hi and is The embodiment of the present Aapparatus shown by way of example in Figs. 2 to 4 is basedk tangular frame 11, Fig. 3, equipped with a sighting wire to which a sighting ball 13 is secured. A spindle 2, parallel to the horizontal bar 1b carries on its smooth left part an externally right` hand threaded tube 2a) rotatable thereon, while its right or front part 2b is provided with an external left hand screw thread. The spindle 2 carries between the said screw threads two spur y wheels' equal in diameter, one of which, 3a, is

rigidly connected to the tube 2a, while the other, 3b. is fast on the spindle 2 itself. Both spur wheels mesh with a spur vwheel 4 fast on a shaft 5 parallel to the spindle 2 and actuated by a clockwork 18 having a constant predetermined running period, namely the measuring period above referred to. The shaft 5 is axially movable in such a manner that at the end of the measuring period the spur wheel 4 is automatically thrown out of engagement with the spur wheel 3b so that the latter may be turned further by the handle disc 2c at the left hand end of the spindle while the spur wheel 3a on the threaded tube 2a remains in engagement with the spur wheel 4 which is stopped as soon as the clockwork is stopped.

A nut 6 locked against rotation on the threaded tube 2a carries a Vertical arm 6a. In the bottom and top ends 6a' and 6a respectively a screw spindle 7 is journalled. A nut 8 locked against rotation on the screw spindle 'I is provided with trunnions 8a. By turning the screw spindle '7 by means of a hand disc 'la secured thereto and a stationary pointer 6b', the nut 8 may be adjusted along the vertical scale 6b graduated by units of time to indicate the altitude or time of falling of the object. The trunnions 8a engage into longitudinal slots 14h in the two halves of the forked end of the sighting rule 14 pivoted on the stud 10 and guided on the arc of a circle 1c and carrying the outer dropping pointer 14e.

A nut 9 locked against rotation on the screw spindie 2b carries a pinperpendicular to said spindle and engaging into the slot 15a of the iirst rule 15 which is pivoied on the stud 13 and guided on the arc of a circle 1c the same as the sighting rule 14 and cerriesthe outer sighting mark 14e. By turning the hand disc 2c 4the two rules 1 4 kand 15 are brought into rtheir initiall positions before the begimiing ofthe measuring period. 'Ihe dropping rule 14 is adjusted to its initial position by properly turning the clockwork 18 until the stop 14a strikes against the end of the screw spindle 17 adjusted to the proper lagging angle by means of the scale 1g for rough adjustment and scale 17a foriine adjustment.

The operation of the apparatus hereinbefore described is very simple. vBy shifting the shaft 5 by means oi' the handle 5a the spur wheel 4 is brought into engagement with the spur wheel 3b, whereupon the gearing 3a, 3b, 4 is actuated bythe hand disc 2c. disc 7a, the position of the trunnions 8a is adjusted by means of the scales 6b and 6b' in accordance with the altitude or time of fall of the object. Then by properly turning the screw threads 2a, 2b by the handle disc 2c the two 95 sighting rules are brought vinto the initial position so that the outer sighting point 14e reaches the position 14e' and the outer sighting point 15o reaches the position 15e. Thereafter the 'air craft is caused to ily directly towards the target and at the moment when the target appears in the first sighting line 13, 15c,that is to say KOK Y of Fig.v 1, the clockwork 18 is started by actuating a button 5b and then the target is kept in the sighting line-during the entire measuring period by properly actuating the hand disc 2c. Thereby the first sighting rule 15 is turned so far that its outer sighting point comes from the position 15e' into the position 15e and the dropping rule .14 is turned so far that its outer sighting point comes from the position 14o into the position 14e. At

y the endl of the measuring period the clockwork automatically shifts back the shaft 5 and disengages the spur wheel 4 from the spur wheel 3b so that the outer sighting point 14e is locked in 115 position. The air craft continues to ily directly towards the target until the latterappears in the sighting line 13, 14e and at this moment the object is dropped. y

'I'he outer sighting point 14c may be dispensed 120 with if the dropping rule is provided with a laterally projecting stop 14d againstwhich strikes a properly arranged stop 15d of the rule v15 when the latter, after the measuring period has lapsed, is turned backwards exactly so farthat the outer sighting point reaches the position 14e; In this case the sighting point 15e serves during the measuring period as the first sighting point and after the Ameasuring period has lapsed, as the throwing off sighting point. l 130 What I claim is: l .Y 1. An aiming apparatus for dropping objects from air-crafts comprising a stud, a sighting point on this stud, a first rule, a sighting rule, both of the said rules beingfrotatably mounted 0n the said stud, a clockwork having a predeterined running period independent oi the height of the aircraft above the ground means for cperatively connecting the said'sighting rules with each otherduring the running period of the said clock work whereby the said rules are simultaneously turned in opposite directions, and means operated by said clockwork to render said connecting means inoperative at the'end of said pe- 2. An aiming apparatus for dropping objects from air crafts comprising a stud, a sighting point on `this stud, a rst rule, a sighting rule, both of the said rules being rotatably mouted on the f said stud, a clockwork having a. predetermined 15 Then by turning the hand 90 running period independent height of the stop on. one ot the said rules and a. stop on the sighting'rule serving as the outersighting point of the other rule whenever the said stops strike against each other, and means operated by said eleckworktorender said connecting means inopsaid period.

erative at the end of omen-me, tnelour point of theme mined 

